PS acceptance and luminosity determination
Pair Spectrometer acceptances were measured using runs with the total absorption counter. The shapes were compared with the detailed Geant simulation.
The normalization of PS acceptances agrees reasonably well, on the level of 5%, for 2018, 2017, and 2016 TAC runs. Note, the acceptance shape for 2016 data
is different due to the larger PS magnetic field. A good agreement in shapes between the measurements and simulation was observed.
Presentations on TAC measurements
Instructions for obtaining measured fluxes from CCDB
A Python script plot_flux_ccdb.py located in hd_utilities will create a ROOT histogram of the PS tagged flux for a given range of runs.
More detailed instructions are provided in the $README on GitHub. Specifically, the energy binning of the histogram and which polarization orientation is histogrammed can be modified with some command line parameters (see README or script help message). On the ifarm you can setup your environment using the nightly build (example below), or your favorite environment setup script to set the relevant CCDB and RCDB variables.
source /group/halld/Software/build_scripts/gluex_env_nightly.csh 2022-02-18
With your environment set you can run the command to create the flux histogram from the database with the command below
python3.6 $HD_UTILITIES_HOME/psflux/plot_flux_ccdb.py --begin-run beginRun --end-run endRun